I would check the specs and make sure it'll do 15 FPS. (frames per second) My S110 does, and it's movies are far superior to a lot of others because many don't do 15 FPS. I don't know if all Canons are the same as that goes, but you should check.
I just ordered an S400 because i too am more concerned with movie mode, and the 400 can do far longer clips than the S110. This is another spec to look for. My 110 only does 10 to 20 seconds depending on the amount of data whatever i'm shooting takes. It usually stops before 15 secs. The 400 is said to go to 3 minutes ! However, they mention something about using a high speed card in order to get that much length. But even if it only goes 1/3 of the way on a low speed card, it's still worlds better than the S110.
Anyway, form what i've seen the Cannons, or at least the ELPH series have the best movie mode of any still camera i've seen. The movies on my 110 look great for what it is, so i can only imagine how the 400 will be.
One thing tho........they tend to often take movies that have a very bad tint to them or are rather fuzzy. This mainly happens when you don't point the camera at the subject and give it a few seconds to focus and correct the color before you shoot. But it will somethimes even happen when you do everything right. Hopefully the 400 will be better. But anyway, what i'm getting at here is that they can almost always be edited to fix them 100%. I use Virtual dub to fix the focus and color, delete frames, and anything else it needs. This is a free program you can download that accepts a ton of plugins that will enable you to take a movie that looks completly worthless and make it look like a gem.
